This invention relates to ferrite resonators and more particularly to coupling structures used with ferrite spheres.
A spherical ferrite is used as a resonator for building microwave tunable devices, such as oscillators, filters, limiters, and the like. In the past a complicated wire loop transducer is conventionally used to couple to the spherical ferrite resonator, which, in order to maximize coupling to the sphere, the transducer or transducers are in the shape of a half circle loop disposed around the sphere so that the wire is at roughly equal distance from the surface of the sphere. This configuration makes the assembly of these devices a time consuming task; making it almost impossible to implement an automated procedure for the purpose of high volume production of these components. What is needed is a configuration and structure to facilitate high volume manufacturability of spherical ferrite based devices.
According to the invention, a spherical resonator device includes a resonant sphere around which transducers for electrical coupling are metallized layers on a flat surface shaped to provide exposure of the resonant sphere to a quasi constant field. In particular, the pattern comprises a transmission line of non-constant width in the region proximate to the sphere where a taper is provided which increases in width with distance from the sphere.
The invention will be better understood by reference to the following detailed description in connection with the accompanying drawings.